The relationships between the myocardial bridge and ramus interventricularis paraconalis characteristics in lamb and sheep

The myocardial bridge (MB) is an anomaly that the myocardial fibres cover on a segment of the subepicardial coronary arteries or their branches in domestic animals and humans. The aim of the present study was to determine the relationships between the characteristics of the MB and ramus interventricularis paraconalis at three levels in lambs and adult sheep. Thirty-three hearts (16 lambs and 17 sheep) were used to determine the MB (length, angle and thickness) and vessel (vessel diameter and thicknesses of tunica intima et media of ramus interventricularis paraconalis) characteristics. Independent-samples t test was applied to compare variables between lambs and sheep. Spearman's correlation analysis was conducted to evaluate the relationships between bridge and vessel characteristics at three bridge levels. Length, angle and thickness of myocardial bridges were not significantly different between the lambs and sheep (p > .05). The mean length, angle and thickness were 24.9 ± 16.1 mm, 113.7 ± 11.2° and 1,098 ± 555 µm in 33 hearts, respectively. In lambs, the mean vessel diameters were 1,930 ± 742 µm (1,534–2,325 µm), 1,247 ± 665 µm (893–1,601 µm) and 865 ± 172 µm (774–957 µm) at the pre-bridge, bridge and post-bridge levels, respectively. In sheep, the mean vessel diameters in the same order were 1,861 ± 1,068 µm, 1,337 ± 308 µm and 1,287 ± 549 µm. The bridge prevalence was 100% in the samples examined. In conclusion, coronary arterial diseases related to myocardial bridge should not be expected in sheep for veterinary cardiology practice. It may also be concluded that the cross-breeds of the Awassi and Chios sheep may be useful in experimental studies related to myocardial bridge surgery.     

Anthelmintic Resistance on an Organized Sheep Farm in India

Monitoring anthelmintic resistance in strongyle nematodes by the faecal egg count reduction test and a commercial larval development assay on an organized sheep farm in the semi-arid area of Rajasthan revealed the emergence of resistance to benzimidazoles and rafoxanide and a potential risk of the development of levamisole/tetramisole resistance. A benzimidazole/levamisole combination, avermectins and closantel were each found to be efficacious.     

Evaluation of subchondral bone mineral density associated with articular cartilage structure and integrity in healthy equine joints with different functional demands

OBJECTIVE: To determine and correlate subchondral bone mineral density and overlying cartilage structure and tensile integrity in mature healthy equine stifle (low magnitude loading) and metacarpophalangeal (high magnitude loading) joints. ANIMALS: 8 healthy horses, 2 to 3 years of age. PROCEDURE: Osteochondral samples were acquired from the medial femoral condyle (FC) and medial trochlear ridge (TR) of the stifle joint and from the dorsal (MC3D) and palmar (MC3P) aspects of the distal medial third metacarpal condyles of the metacarpophalangeal joint. Articular cartilage surface fibrillation (evaluated via India ink staining) and tensile biomechanical properties were determined. The volumetric bone mineral density (vBMD) of the underlying subchondral plate was assessed via dual-energy x-ray absorptiometry. RESULTS: Cartilage staining (fibrillation), tensile moduli, tensile strength, and vBMD were greater in the MC3D and MC3P locations, compared with the FC and TR locations, whereas tensile strain at failure was less in MC3D and MC3P locations than FC and TR locations. Cartilage tensile moduli correlated positively with vBMD, whereas cartilage staining and tensile strain at failure correlated negatively with vBMD. CONCLUSIONS AND CLINICAL RELEVANCE: In areas of high joint loading, the subchondral bone had high vBMD and the articular cartilage surface layer had high tensile stiffness but signs of structural wear (fibrillation and low failure strain). The site-dependent variations and relationships in this study support the concept that articular cartilage and subchondral bone normally adapt to physiologic loading in a coordinated way.     

Estimates of genetic parameters for faecal egg count of Haemonchus contortus infection and relationship with growth traits in Avikalin sheep

Genetic parameters for faecal egg count were estimated in naturally challenged Avikalin sheep developed and maintained at Central Sheep & Wool Research Institute, Avikanagar, India, over a period of 4 years (2004–2007). The data on faecal egg count for 433 animals descended from 41 sires, and 151 dams were used for the study. Genetic analyses were carried out using restricted maximum likelihood, fitting an animal model and ignoring or including maternal genetic or permanent environmental effects. Direct heritability for the trait was 0.149 ± 0.096 when maternal effects were ignored. In the model which takes in to account direct genetic, maternal genetic and maternal permanent environment effect together, it was observed that maternal heritability (m²) accounts for 0.6% of total variation whereas maternal permanent environmental effect (c²) accounts for 6.14% of total phenotypic variation. Effect of faecal egg count on the growth characteristics was observed to be significant. It was seen that wherever FEC was high, body weight or average daily gain declined in active infective stage. After termination of the infection, these effects were found to be non-significant. Result suggests that direct genetic and maternal permanent environmental effects were important for this trait; thus, they need to be considered for improvement in the trait.     

Characteristics of repeat breeding buffaloes in Nepal

Repeat breeding is one of the most important reproductive disorders in buffaloes. Its etiology, however, is not well described. The aim of this study was to show the clinical features of repeat breeding buffaloes referred to infertility camps in the southern region of Nepal. Eighty-five buffaloes mated three times or more without conception were clinically examined. Sixty percent of the buffaloes were heifers. Fifty-nine percent of the buffalo cows with repeat breeding were already 10 months or more after calving. Indications of cervicitis were observed in 25% of the repeat breeders. Buffalo cows 12 months or more after calving and heifers in adequate nutritional condition were treated with either GnRH or PGF2alpha, and showed a satisfactory conception rate after treatment. Cows within 12 months post partum and heifers at a relatively younger age were treated with a vitamin/mineral mixture supplement, and this resulted in a moderate conception rate. In conclusion, the major clinical features of repeat breeding buffaloes include a large proportion of heifers, a long interval from calving to treatment, a high incidence of cervicitis, and a high or moderate response to treatment with PGF2alpha and GnRH or vitamin/mineral mixture. More attention needs to be paid to estrous detection and management of mating with bulls.     

Impact of Management Practices on Grain Yield and Grain Protein Relationships in Durum Wheat

We examined the relationship between grain yield (GY) and grain protein concentration (GPC) in durum wheat ( Trticum turgidum L. var. durum ) as affected by N application rate, seeding rate, and irrigation levels. Field experiments were conducted for four years with five N rates, five seeding rates, and four Irrigation regimes: A. Only a preplant irrigation; B. A + one irrigation at tillering; C. B + one irrigation at booting stage; and D. C + one irrigation at early soft dough stage. These treatments produced a large variation in GY and GPC which provided the basis for examining the GY-GPC relationship by all possible correlation analyses and by analysis of variance after partitioning the bivariate responses (GY and GPC) into pairs of univariate responses. The contribution of N, seeding rate, and irrigation on parallel (simultaneous changes in the same direction) and opposite changes in GY and GPC was determined. The effects of N and seeding rate on parallel increase in GY and GPC were significant. For a given level of irrigation, increasing N application resulted in significant parallel increase in GY and GPC to the highest level of N. At low N levels, increase in irrigation level from A to B increased GY and decreased GPC; however, it was not true at higher N levels. For a given N level, GY plateaued at irrigation C, whereas GPC increased up to irrigation D. The overall effects of irrigation treatments on parallel changes (positive correlation) in GY and GPC significantly outweighed their effects on opposite changes (negative correlation) in GY and GPC. Increasing levels of N and irrigation improved the correlation between GY and GPC and the yield-protein index. This study suggests that with proper management practice it is possible to increase both GY and GPC simultaneously and obtain high protein yield ha⁻¹.